condition mean min max ZT0-3 11.88645 11.88645 11.88645 ZT4-7 7.120035 7.120035 7.120035 ZT8-11 6.457755000000001 6.457755000000001 6.457755000000001 ZT12-15 9.451 9.451 9.451 ZT16-19 12.7132 12.7132 12.7132 ZT20-23 15.3287 15.3287 15.3287